In [6]:
import numpy as np
import matplotlib.pyplot as plt
import random as rn
from matplotlib.animation import FuncAnimation
from matplotlib import colors
In [5]:
%matplotlib notebook
In [6]:
x = np.zeros((200,200), dtype = int)
fig = plt.figure(figsize = (6,6))
ax = plt.subplot(111)
plt.title("Animation test")
cmap = colors.ListedColormap(['palegreen', 'green', 'orange', 'black'])
im = ax.imshow(x, cmap = cmap, vmin = -1, vmax = 2)
def animate(i): # Test function
global x # Allows the variable x to be treated as a global variable
x=np.random.random(x.shape) # Produce a random 2D array
im.set_data(x) # Used to retreive data to be plotted, in this case x
return im
anim = FuncAnimation(fig=fig, func=animate, interval=100, blit=True, repeat=False)
plt.show()
Using embedded HTML¶
This method has an extra step in order to view the animation. With this method, we need to import the HTML function to embed HTML code into the notebook. The cell below uses almost the exact same code as the previous animation. I have however changed how each frame is updated in the animate function.
In [2]:
x = np.zeros((200,200), dtype = int)
fig = plt.figure(figsize = (6,6))
ax = plt.subplot(111)
plt.title("Animation test")
cmap = colors.ListedColormap(['palegreen', 'green', 'orange', 'black'])
im = ax.imshow(x, cmap = cmap, vmin = -1, vmax = 2)
def animate(i): # Test function
global x # Allows the variable x to be treated as a global variable
for a,b in [(a,b) for a in range(200) for b in range(200) if a+b == i]:
x[a,b]+=1 # Adds a diagonal of 1's
im.set_data(x) # Used to retreive data to be plotted, in this case x
return im
anim = FuncAnimation(fig=fig, func=animate, frames=400, interval=100, repeat=False)
# We use the optional frames arguement to tell Python how many
# frames to create.
# Also, no blit
plt.show()
In [16]:
anim_html = anim.to_jshtml() # This builds HTML code for the animation
In [17]:
from IPython.display import HTML
HTML(anim_html) # The HTML function allows us to embed the html code in the notebook
Out[17]:
The following code writes an .html file in the current directory that contains the code for the animation. The animation can then be viewed by opening the newly-created .html file in the browswer.
In [11]:
f=open('anim.html','w') # Opens a new file called anim.html and stores the open file in the variable f. The 'w' means
# the file is opened and can be written to.
f.write(anim_html) # Writes the HTML code stored in the variable anim_html to the file anim.html
f.close() # Closes the file. Always close the file when you are done with it.
Counting the neighboring 1's¶
In [10]:
A = np.random.randint(0,2,(10,10))
print(A)
In [12]:
sub = A[3:6,5:8] # 3x3 array surrounding (4,6) entry in A
print(sub)
In [13]:
sub.sum()
Out[13]:
In [14]:
B = np.random.randint(0,3,(10,10))
print(B)
In [15]:
sub = B[3:6,5:8] # 3x3 array surrounding (4,6) entry in B
print(sub)
In [16]:
count = 0
for i,j in [(i,j) for i in range(3) for j in range(3)]:
if sub[i,j] == 1:
count += 1
print(count)
In [18]:
sub = B[5:8,8:11]
print(sub)
In [22]:
def count_1s(array):
count = 0
m,n = np.shape(array)
for i,j in [(i,j) for i in range(m) for j in range(n)]:
if array[i,j] == 1:
count += 1
return count
In [23]:
count_1s(sub)
Out[23]: